Conventionally, a wall surface of buildings has been covered and decorated by exterior wall decorative sheets. In recent years, so-called solar panel constituted by attaching solar cell elements to the exterior wall decorative sheets has been provided to generate electric power as well as the decoration. In particular, a photovoltaic power generation has been remarked as an ecological energy, independent of fossil fuels.
For example, Japanese Utility Model Laid-open Publication No. 22755 of 63 (Showa) discloses an installation structure of exterior wall decorative sheet to install holding members having a substantially letter “L” in section at upper and lower positions on a wall surface of a building and a plurality of connectors at an upper end of the holding member. On the other hand, it discloses the installation structure to install engagement strips at upper end of the holding member on a back surface of the exterior wall decorative sheet (solar panel) having built-in solar cell elements and an output terminal connected to a connector of the holding member in the engagement strip. Furthermore, it also discloses the installation structure to install wire collection connected among a plurality of connectors along the holding member, fix mechanically a plurality of exterior wall decorative sheets through the engagement strips to the holding member, and also connect electrically among solar cell elements attaching to a plurality of exterior wall decorative sheets.